Earlier Hematuria Improvement Is an Independent Predictor of Remission in Patients with Primary Membranous Nephropathy and Nephrotic Syndrome

Background: Prognostic value of hematuria in primary membranous nephropathy (PMN) patients with nephrotic syndrome (NS) has not been well understanded. We investigated the earlier hematuria improvement in PMN patients with NS receiving immunosuppressive (IS) therapies to illuminate its prediction capacity for the treatment response and remission status at 12 months. Methods: This is a single-center retrospective study. From 1 January 2021 to 30 April 2024, patients with biopsy-proven PMN and NS starting IS therapy after renal biopsy were recruited. The main exposures were baseline hematuria and hematuria disappearing at 6 months. The outcomes was nephrotic remission status at 12 months. Binary logistic regression models were used to estimate the relationship between exposures and outcomes. Receiver operating characteristic (ROC) curves were generated to evaluate the predictive performance of exposures. Results: One hundred and thirteen patients met the eligibility criteria, and 98 (86.7%) had hematuria at the renal biopsy. Patients with hematuria had higher baseline serum Cr and h-CRP, and had lower remission rate at 12 months (65.3% vs 86.7%, P=0.041). In the subgroup of patients with hematuria, 29 out of 98 (29.6%) had hematuria disappearance at 6 months. There were no significant relations between baseline hematuria levels and other clinical data and treatment response. Hematuria disappearing at 6 months was significantly correlated with lower 24-h UTP and higher serum ALB at both 6 and 12 months , and higher nephrotic remission rates at 12 months (82.8% vs 49.3%, P=0.002). Logistic regression model demonstrated that for patients with hematuria, hematuria disappearance at 6 months was an independent predictor for nephrotic remission at 12 months (OR=0.202, 95%CI: 0.069-0.592, P=0.004). ROC curve analysis revealed that the area under the curve (AUC) for predicting nephrotic remission at 12 months based on hematuria disappearance at 6 months was 0.644 . Conclusion: Patients with PMN and NS have high prevalence of glomerular hematuria. Patients without hematuria or negative-conversion of hematuria at 6 months after IS treatment have higher nephrotic remission rates at 12 months. For patients with hematuria, hematuria disappearance at 6 months was an independent predictor for nephrotic remission at 12 months.